GA2 Quiz 1

How many benes are in the cranium

22 named bones

What is the neurocranium?

Bony case of brain and membranous coverings

How many bones are in the adult cranium?

8, four single and two double

What is the viscerocranium?

Anterior parts of the cranium

What kinds of bones compose the skull?

Flat and Irregular

What kind of joint is the temporomandicular jjoint

Condyloid type of synovial joint

What landmarks make the orbitomental plane? (Frankfort horizontal plane

Inferior margin of the orbit, superior margin of the external acoustic meatus

What bony feature is also its own bone?

Inferior Nasal Concha

What two bones make up the lambdoidal suture?

Parietal and Occipitial

Where is the lambda?

Where the sagital and lambdoid suture meet

Where is the Asterion?

Meeting point of parietal, occipital, and temporal bones

Where is the Pterion?

Meeting of 4 bones/sutures. Sphenoid, parietal, frontal, and temporal

Where is the Vertex?

Highest point of skull

What happens is the Pterion is fractured?

Middle meningeal artery is ruptured

Where is the Bregma?

Meeting of coronal and sagittal sutures

What are Wormian bones?

Sutural bones made in the skull

What are pneumatized bones?

Bones with air spaces/sinuses

Which bones are pneumatized?

(FEST) Frontal, ethmoid, sphenoid, temporal

What is another name for the EOP?

Inion

Where is the gonion?

Angle of mandible

Major embryonic sources of skull

Neural crest cells and paraxial mesoderm

What does the membranous neurocranium ossify into?

Flat bones of cranial vault

What does the cartilaginous neurocranium ossify into?

Skull base (Chondrocranium)

Where does skull growth occur?

Sutures and synchondroses

What is intramembranous ossification type?

Mesenchyme directly becomes bone

What is Endochondral ossification type?

Cartilage model is replaced by bone

What kind of bones mainly use intramembranous ossification?

Flat vault bones

What bones primarily use endochondral ossification?

Skull base bones

What is the viscerocranium mainly derived from?

Pharyngeal arches 1 and 2

What makes up the first arch of the viscerocranium?

Maxilla, zygomatic bone, mandible, malleus, incus

What makes up the second arch of the viscerocranium?

Stapes, styloid process, part of hyoid bone

What can result from errors in pharyngeal arch development?

Facial form and hearing

What are fontanelles?

Fibrous gaps between developing calvarial bones

What do fontanelles do?

Permot brain growth and overlapping of bones during birth

Which fontanelle is most clinically important?

Anterior

What is learned from assessing fontanelles?

Evaluates hydration and intracranial pressure

Shape and closing of the anterior fontanelle type

Diamond-shaped and closes at 18 months

Shape and closing of posterior fontanelle

Triangular and during infancy around 1 year

Closing of sphenoidal and mastoid fontanelles

Closes earlier, less palpable

What can remain between frontal bone halves?

Persistent metopic suture

What is molding?

Temporary change in shape of fetal skull during birth

Why does molding occur?

Cranial vault bones can overlap sutures

What rapidly expands the calvarial during infancy?

Brain growth

True or False: sutures remain open of accomodate brain growth

True

Why is the face small at birth?

Jaws and sinuses are underdeveloped

What else help shape adult face?

Paranasal sinuses and permanent teeth

What is craniosynostosis?

Premature fusions of one of more ranial sutures

What is the result of craniosynostosis?

Growth is restricted perpendicular to closed suture, compensatory growth changes head shape

What are the types of craniosynostosis?

Scaphocephaly/Dolichocephaly, Plagiocephaly, Oxycephaly/ Turricephaly

What suture is affected during scaphocephaly/ dolichocephaly?

Sagittal suture

What suture is affected during plagiocephaly?

Unilateral coronal or lambdoid suture

What is acrania?

Failure of cranial vault formation

What is microcephaly?

Reduced brain and skull growth

What does the skull develope from?

Neural crest and mesoderm